1. Field of the Invention
This invention relates to rotary engines and in particular to means for cooling the rotor of such engines.
2. Description of the Prior Art
In one conventional form of rotor structure utilized in rotary engines and the like, the rotor is made hollow and is provided internally with a liquid coolant which cools the outer surfaces of the rotor by movement thereagainst as a result of the rotating centrifugal field. Lubricating oil is an example of fluids used in such heat exchange means.
A cooling arrangement for rotary mechanisms is illustrated in U.S. Pat. No. 3,042,009 of Walter G. Froede et al. In the Froede et al. patent, each apex portion of the rotor is provided with a heat transfer medium, such as sodium or copper, extending into heat transfer association with a cooling liquid circulating through the rotor. Passage means are provided for supplying a cooling liquid through an internal passage means and to the bearing means.
In U.S. Pat. No. 3,168,237 of Hanns-Dieter Paschke, a stationary hollow disc is provided within a hollow rotor. The disc includes scoop or outflow passages through which the centrifugal forces on the fluid coolant force the fluid when the fluid within the rotor reaches a level sufficient to cover the radially outer ends of the passages. A rotary, axially movable open annular channel member is carried by the rotor at one end face to bear elastically against the housing end wall. The channel member includes pocketlike recesses facing inwardly for collecting the coolant emptying from the outflow conduits in the rotor end face and facing axially outwardly for conveying the coolant to outlet passage means in the housing end wall.
Max Bentele et al., in U.S. Pat. No. 3,176,915, show a cooling system for a rotary mechanism arranged to direct a small amount of oil into compartments in the rotor at predetermined rotative positions of the rotor. The oil is substantially scavenged from the rotor compartments before the rotor reaches a predetermined position at which additional oil is directed therein permitting the rotor to run with only a relatively small amount of oil therein during rotation.
In U.S. Pat. No. 3,204,614, Reinhold Huber discloses a rotary piston for use in an internal combustion engine wherein the piston includes wall means defining a space for receiving cooling liquid extending over a substantial portion of the width of the piston in the axial direction. Means are provided for supplying cooling liquid to the space in radial directions at the corners of the piston with means for discharging the cooling liquid from the space being provided intermediate the corners.
Hanns-Dieter Paschke, in U.S. Pat. No. 3,206,109, shows fluid cooling means for the rotor of a rotary mechanism wherein a plurality of circumferentially spaced cooling compartments are provided in the rotor. Supply and drain openings are provided such that the compartment will not be completely drained and thereby cause the incoming cooling fluid to be mixed with a portion of the cooling fluid previously in the compartment for an increase in the volume of cooling fluid available for cooling the rotor walls. The inlet opening is disposed adjacent the radially inner portion of the compartment. The outlet opening may be provided in the rotor end wall.
In U.S. Pat. No. 3,705,570 of Max Ruf, a liquid cooled rotor is disclosed utilizing centrifugal forces in the shaft and rotor to pump and channel lubricating and cooling oil through the hollow rotor with the internal cavity of the rotor being contoured to assist in pumping and directing the flow. The rotor is provided with a central web extending radially inwardly substantially midway between each pair of apices. The shaft is provided with an axial bore for supplying the cooling and lubricating fluid.